Kenwood KAC-8103-D Service manual
POWER AMPLIFIER
E,M type
K type
Dressing Panel
(A21-6567-02): (K type)
(A21-6580-02): (E,M type)
Fuse (40A)
(F52-0016-05)
Accessories
(W01-1606-05)
Screw set
(N99-1794-05)
Connecting cord assy
(E30-6145-05)
19cm
Accessories
(W01-1607-05)
KAC-8103D
SERVICE MANUAL
© 2006-11 PRINTED IN JAPAN
B53-0473-00 (N) 955
This product complies with the
This product uses Lead Free solder.
RoHS
directive for the European market.
KAC-8103D
BLOCK DIAGRAM
L
LINE IN
(0.2-5V)
R
L
LINE OUT
R
L
L
R
R
SP INPUT
IC11
ISO-AMP
IC32 (2/2)
SUMMING
AMP
IC32 (1/2)
TRIANGLE
WAVE
NF
IC14
I.F.S
15Hz
25Hz
S3
I.S.F
SEL.
IC31
COMP
IC61,64
RESONANCE
DET
Q25,26,28,42
15V
AVR
VR1
SENS.
VOL
IC12,13
DEAD
TIME
IC18
VR2
Q151
MUTE
Q401,402, Q405-409,
404,417
LEVEL
SHIFT
Q400,403
D-AMP
ON/OFF
IC62,63
Q604-607
OVERLOAD
DET
Q416
+HB
B
AVR
L.P.F
FREQ
(50-200Hz)
Q603
414,415
DRIVE
IC60
THERMAL
DET DET
IC1
DC/DC
CON
Q1-3
POWER
ON/OFF
IC15
FREQ=40Hz
BASS
BOOST
LEVEL
0-18dB
VR3
ATT
Q410-413
FINAL
MOS-FET
Q608-611
DC-OFFSET
LC FILTER
LC FILTER
POWER
INDI.
SP
OUTPUT
300W / 4
500W / 2
P-CON
BATT.
GND
COMPONENTS DESCRIPTION
● AUDIO UNIT (X09-8600-10)
Ref. No. Application / Function Operation / Condition / Compatibility
IC1 DC/DC converter IC Generates drive signal for switching element.
IC11 Isolation amp. Isolates noises caused by potential differences in GND.
IC12,13 (2/4) NAND
IC13 (1/4) (4/4)
Pulse conversion circuit Converts pulse width from 1 mm to 10 mm.
IC14 INFRA SONIC FILTER Cuts off ultra low frequency of an audio signal.
IC15 BASS BOOST Bass boost (Variable level)
IC18 LOW PASS FILTER Cuts off high frequency of an audio signal.
IC31 Comparator Digitalizes by comparing analog signal with triangular waves.
IC31,32 (1/2) Triangular wave generation Generates reference signals for digitalizing analog signals.
IC32 (2/2) Error amplifier Compensates for errors by feedback from the output.
IC60
Attenuation circuit to attenuate
input signal by 1.5dB
Comparator in resonance Detects short SP output circuit, measures overcurrent in the circuit, activates
IC61,62,64
detection circuit protection operation.
IC63 (1/2) Comparator circuit Turns off DC/DC power supply when an error is detected.
IC63 (2/2) Comparator circuit Turns off Dclass amplifier when an error is detected.
Q1~3 PCON switch Turns on the circuit when ON signal is applied to the PCON circuit.
Generates and shapes the inverted waveform and to create dead time in Dclass section.
Attenuates output when temperature in the set becomes too high.
2
KAC-8103D
COMPONENTS DESCRIPTION
Ref. No. Application / Function Operation / Condition / Compatibility
Q4,5 Mute Generates mute drive signal and turns off LED.
Q8~11 Gate driver Gate driver in DC/DC converter FET
Q12,13,19,20
Q25,26,28,42
Q29,30
Q37,38
Q151 Mute Turns off audio signal.
Q400,403 Dclass amplifier switch Turns on or off Dclass amplifier.
Q401,402
Q404~409
Q414,415,417
Q410~413 Power amplification High-current switching in Dclass.
Q416 HB 15V AVR Stacking AVR to obtain High+B for Dclass.
Q603
Q604~607 Current-voltage conversion Converts current to voltage to detect overcurrent and sends it to the comparator.
Q608~611 Latch circuit Detects overvoltage in output and retains the current.
DC/DC converter DC/DC converter switching
AVR ±15V AVR
Tracking when ±15V AVR is turned OFF
DC/DC converter pulse ON/OFF control
Pulse amplification, shaping and
level shift
Attenuation circuit to attenuate
input signal by 1.5dB
Matches the trailing edge of ‘-15V’ AVR with that of ‘+15V’ AVR.
ON or OFF DC/DC converter drive waveform.
Generates signal that drives the final FET in Dclass.
Attenuates output when temperature in the set becomes too high.
CIRCUIT DESCRIPTION
■ Resonance detection and protection technique
• Measures against SP terminal’s shortening
Since resonance voltage is generated with an output LC filter ,
during the time after shortening until a shor t circuit current is
generated, detect resonance voltage and turn D-POWER off .
Resonance voltage
L
Current
Impedance and terminal contact resistance are inherent in the circuit.
Therefore, resonance voltage is generated at both
ends of a shorted C.
But resonance voltage occurs less when shortening at a low output voltage point.
generating point
Output
C
Short
Output
• Circuit description
Resonance voltage caused by shortening is detected through
a high pass filter.
Filter characteristics is 2kHz cut-off and -18dB attenuation.
q At 100Hz, voltage is attenuated up to -59dB of 10.6V and
peak voltage becomes 12mV.
w At 200Hz, voltage is attenuated up to -44dB of 10.6V and
peak voltage becomes 6.7mV.
e Since resonance voltage frequency is 3.7kHz, voltage does
not attenuate.
Therefore, only resonance voltage can be detected.
100k
10V10V
100k
0.01u 0.033u 0.033u
IC64
(1/2)
22k
10k
2.2k
IC64
(2/2)
to Dclass,
power off
control
1k
15k
0.01u
100k
15V
4.7k
3
A B C D E
D600
4
D8
Q603
R
2
KAC-8103D
1
PC BOARD (FOIL SIDE VIEW)
AUDIO UNIT
X09-8600-10
(J76-0348-01)
W160
R46
W158
C22
C23
R47
C21
C20
W123
W161
W124
W159
W146
W154
Q411
W147
W152
L2
W150
W151
C119
C118
C195
R424
W148
W149
W144
W194
W137
W145
W134
W135
C116
R416
W143
C100
W129
C197
C198
W140
C196
W141
W138
SDGSDG SDG SDG
W139
W133
W136
W120
R203
R606
R607
C619
W122
W121
W96
W97
W86
W87
R423
D3
R412
C15
W116
W118
W114
W331
R6
W317
W318
Q2
R2
D4
W109
W119
W117
W113
W115
VR3
B.B
Q409
BE
R417
W89
W108
W107
D6 D7
R5
Q1
BEBE
R4
W110
W106
W316
W314
Q408
W105
W99
Q3
BE
D12
C221
R420
R414
Q415
EB
EB
R9
R8
C6
R14
R7
R3
Q5
D5
R73
C2
W98
W101
W315
W91
W92
W93
W100
R236
C224
R411
Q405
W94
W90
W95
C404
R74
BE
D10 D11
R13
D9
R636
R618
R620
IC60
58
C220
R231
IC15
14
R235
R409
E
B
R410
C5
R230
58
W312
R234
Q404
R402
R422
R10
C4
R11
C3
C601
R637
14
VR2
LPF
R214
R406
BE
EB
R403
BE
Q400
R405
C402
E
Q
R12
BE
Q4
R646
C605
C606
B
R65
W85
R233
C218
W204
C217
D606
W313
Q410
R415
R419
W170
2
+B
C25
R48
3
D19
W191
W192
W185
W186
W175
W174
C26
W171
W173
R425
R439
R49
-B
Q412 Q413
R418
C401 C405
W155
W156
W157
R426
R438
W164
W165
W162
W163
P3
D18
W187
SDGSDGSDGSDG
Q12Q13Q19
4
C19
W500
W189
5
D13
6
Q20
R43
R41
R37
R39
W196
BE
Q10
R27
R25
R24
BE
R29
Q6
16 9
C7
W193
W324
R18
C11
R20
W329
C12
C13
R19
W325
R23
W330
C24
W127
W195
C10
R15
R16
W188
R45
W190
R38
BEBE
Q8
BE
Q11
BE
Q37
D17
IC1
W323
W322
R22
W125
R44
R40
81
C16
C18
W112
R42
BE
W321
R21
C17
W180
W102
W103
W320
R26
Q9
Q38
W167
W181
R17
W182
W319
C14
C1
W202
C42
TH1
L1
D1
D2
W203
W128
L3
C41
P1
W176
W168
W166
W197
W198
W199
W200
R1
W172
W201
W169
J3
7
4
JIHGF
D10 D11
C5
R74
R230
BE
KAC-8103D
1
R409
04
60
5
4
235
W312
R410
R11
R637
1
8
R234
R214
Q404
R402
R422
R10
C4
C3
C601
VR2
LPF
R406
BE
EB
R403
BE
Q400
R405
C402
E B
Q416
R12
BE
Q4
R646
C605
C606
BE
R652
W85
R233
C218
W204
C217
D400
R421
R634
R629
D8
D606
Q603
W313
Q401
BE
R401
D600
W79
W80
W81
W82
W84
D151
R152
R653
EB
Q407
R408
Q403
D403
D404
W83
Q151
BE
C516
R223
C212
S3
IFS
R440
W78
D407
W311
R208
R209
R151
R407
W77
R225
P2
C40
Q414
EB
R400
R413
EB
EB
Q417
Q406
EB
R404
Q402
W68
R644
R639
C403
W74
W72
D406
D405
R638
W73
R630
71
IC13
814
C620
R632
C618
W70
W61
41
W75
C152
R154
R153
R155
58
R160
R156
C155
C151
R161
R504
C507
R163
R226
R224
C216
R213
58
W205
IC18
14
W76
R222
W310
W309
C215
C209
VR1
SENS
W71
C211
R221
W69
IC32
C214
W67
R640
C614
C634
R633
R301
C303
R158
C154
R157
C153
C205
C613
R641
C622
W66
R220
W111
W55
Q610
Q609
BE
BE
Q608
W64
D610
W63
W65
R309
R303
C304
R302
W62
R159
C156
R211
58
IC14
14
R206
R218
R219
R217
C612
W60
R162
W184
BE
W54
W49
C202
R216
W88
W59
C210
R642
D605
R651
W58
W50
W57
D182
W46
R647
W56
W327
C213
W44
W45
W48
W52
D611
R654
R650
W42
W43
R205
Q26
W29
Q25
B
R52
Q611
D613
BE
R643
C615
BE
BE
Q612
Q602
R635
R645
58
IC63
C631
14
R649
R648
D186
17
IC12
814
R183 R184
C183
C182
R308
R306
W328
W326
R307
41
C305
IC31
58
R305
C306
C201
R204
W47
D107
W51
W53
R207
C105
C107
R111
R107
J2
EB
15V
R53
E
Q30
BE
R65
C31
D23
R627
C611
W38
R625
R626
C610
R623
W183
W31
W33
W39
W36
14
W40
R617
R182
D608
W307
W35
D183
D303
D304
R304
W41
D305
W34
W37
C106
W308
R110
R109
R108
1
2
C35
R64
W25
R66
W22
W30
+15V -15V
Q606
BE
EB
Q607
R624
Q604
BE
EB
Q605
R628
C623
C624
R656
R657
D609
C616
R621
R622
58
IC64
W26
C609
D607
C608
R619
C181
W305
D306
D308
W28
D307
C200
W32
W27
D108
W306
C104
R112
C538
R538
J1
C117
D101
C108
W24
D181
W23
C503
R104
C36
W21
R106
D612
R631
C617
C632
W20
R181
R503
R122
R102
W18
R601
D603
D602
W304
R120
C111
R119
C110
EB
W8
R58
Q29
R67
BE
R655
W16
C630
D601
R609
IC61
14
W14
W15
R121
C112
R123
IC11
14
R116
R113
R105
C101
C102
W17
R101
-15V
BE
R61
C32
D25
58
IC62
14
C600
R600
D604
R614
R611
58
W13
C633
R613
R502
R500
W10
C500
R117
C113
58
C109
R115
W303
R114
R103
R100
Q28
W11
R616
R615
W12
C103
Q42
R604
W9
C502
W19
W302
D103
C504
R603
R602
R612
W7
W6
R501
D104
R57
C602
C114
C115
C603
C604
W5
Q601
R610
W301
Q600
W300
X09-8600-10
Ref. No. Address
IC1 6B
IC11 6H
IC12 4G
IC13 4F
IC14 6F
IC15 6E
IC18 6F
IC31 5G
IC32 5F
IC60 5E
IC61 4H
IC62 3H
IC63 4G
R605
BE
BE
R608
W2
IC64 4G
Q1 4E
Q2 4E
Q3 4E
Q4 4E
Q5 4E
Q6 6A
W3
W1
C607
Q8 5B
Q9 5B
Q10 5A
Q11 5B
Q12 4A
W4
Q13 4A
Q19 5A
Q20 5A
Q25 2G
Q26 2G
Q28 2H
Q29 2H
C501
Q30 2G
Q37 6B
Ref. No. Address
Q38 5B
Q42 2H
Q151 5F
Q400 2F
Q401 2F
Q402 3F
Q403 2F
Q404 2E
Q405 2E
Q406 2F
Q407 2F
Q408 2E
Q409 2E
Q410 2B
Q411 2D
Q412 2C
Q413 2D
Q414 2F
Q415 2E
Q416 4F
Q417 2F
Q600 3H
Q601 3H
Q602 3G
Q603 5F
Q604 3G
Q605 3G
Q606 3G
Q607 3G
Q608 3G
Q609 3F
Q610 3G
Q611 3G
Q612 3G
2
3
4
5
6
Refer to the schematic diagram for the
values of resistors and capacitors.
7
5
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